A lot, a little and is it just enough? Thermal grease

runt23Jul 9, 2006, 3:18 AM

The grease, from what I understood, was purely to fill the gaps between the tiny microscopic crevases in the place of contact.

So...the big question. How much should I use?

I've thought of cutting out some metal plates, clamping them together to see how far the grease would spread. Just to get an idea, but around town i've heard you want enough that when you press the cooler and cpu together you get a small ammount of grease to leave, which makes sense.

Common sense tells me not much, but from personal experience, approx how much should I add? =)

Just as thin of a solid even layer as you can apply which will be less than the thickness of thin notebook paper, with thermal compound less is the best, too much acts as an insulator rather than a transmitter of the heat.

I keep a single edge razor blade on hand for spreading thermal compound, it works great for getting an even smooth coat, it doesn't hurt to do a test fit of the heatsink and pull and inspect it for coverage to see if you're using too much.

I always clean up with 70% Isoprophyl Rubbing Alcohol, and usually Qtips, followed by a short burst of canned air, to make sure no particles of the Qtip is left behind.

The grease, from what I understood, was purely to fill the gaps between the tiny microscopic crevases in the place of contact.

So...the big question. How much should I use?

I've thought of cutting out some metal plates, clamping them together to see how far the grease would spread. Just to get an idea, but around town i've heard you want enough that when you press the cooler and cpu together you get a small ammount of grease to leave, which makes sense.

Common sense tells me not much, but from personal experience, approx how much should I add? =)

In the pictures from the link, it appears that the ammount of paste used is very small. On my last build I used a lot more and had some cleanup to do. No problems obivously, but I like a clean system =)

The grease, from what I understood, was purely to fill the gaps between the tiny microscopic crevases in the place of contact.

So...the big question. How much should I use?

I've thought of cutting out some metal plates, clamping them together to see how far the grease would spread. Just to get an idea, but around town i've heard you want enough that when you press the cooler and cpu together you get a small ammount of grease to leave, which makes sense.

Common sense tells me not much, but from personal experience, approx how much should I add? =)

I found the THG video on testing socket 775 motherboards very helpful in this regard. The video shows the techie adding the CPU and then the thermal paste, then the heat sink several times to different motherboards. Each time the techie just added a dab of thermal paste about the size of a grain of rice to the center of the CPU. If you watch them remove he heat sink you see an even layer of thermal paste spread across the CPU. Its a really good video.

Vodka would have contamnents that could affect thermal performance, just use the purest alcohol as you can find, over 91% is prefrable.

To paste the chip, use a very small dab on the edge of a business card and spread it as thin as possible over the entire core surface. Push down with enough force to not quite make the paste come back up from the core surface. Putting a dab in the middle and hopeing it spreads evenly isn't a good idea as you will certainly use more than you need and probably not cover it all.

I've had a small tube of AS5, 3.5g, cover almost 50 chips, AS's site says only 15-25 but that's just marketing (We suggest you use more so we can sell more.) It should last a LONG time if you use the right amount.

It is found from Tom's Hardware home page. Look for "Resource Center" box on right of page. Click videos. Download "THG video 17" dual-core stress test AMDvs.Intel. Sorry, I gave the wrong video in earlier post.

It is found from Tom's Hardware home page. Look for "Resource Center" box on right of page. Click videos. Download "THG video 17" dual-core stress test AMDvs.Intel. Sorry, I gave the wrong video in earlier post.

I don't know why I cannot find the "resource center". I looked on the home page and even did a site search. :?

Since I switch to a Zalman 7700, I find it better to just spread the compound with a razor.

So the difference I'm try to say, if it is an installation to where you drop the HSF down, then lock it, the dot would be best, in my opinion.

And if it isn't, like my Zalman, its going to move around while you try to line up the screw holes, and so you may not have a perfect dot on the heat spreader on the CPU. That is why I find it better just to cover the top based on that the 7700 installation.

Hey R,4Ry is right, ya only need enough to evenly cover the cpu from edge to edge with a thin coat of Arctic Silver 10, (if your using that product) That's what I used for my processor.Like 4 said, use isopropyl alcohol to clean BOTH surfaces, then apply a small bead of compound (about the size of a shotgun pellet) then carefully spread the compound outwards towards the edges. YOu will know if the spread is even by the way the coat lies on the cpu. Make sure you use a new razor blade, cuz any nicks on the razorblade will leave "tiny mountains" of grease when you spread.

Before I go any further, YOU DO have your mobo OUT of your case right? don't know about anyone else but I prefer the mobo out of the case when doing this because that way once the heatsink is seated on the cpu, you can get a good side view of the seat to be certain of a proper seat.

Once you have seated the heatsink on the cpu, carefully use a 1/4 twist turn side to side to assure a good contact. Then RE-ALLIGN the heatsink and clamp it down. DOUBLE CHECK for a proper even seat before you put it back in your case.

Now your ready to fire it up. I don't what anyone else does but I like to enter the bios in the hardware monitor section and I watched my cpu temp for a few minutes just in case I saw any temp spikes. That way I can always do a quick shutdown. If all goes well, then your good to go with your new beast !!! :wink:

Expect the cpu to run a bit higher than normal (say 5 -15 F ) for a while as the thermal paste has a chance to settle in. Arctic Silver says about 200 hours run time. And starting up and shut downs are OK because this will give it some heat settling after the case fans stop running. Now my Athlon X2 4800+ dualie runs as smooth as a "prom Queen's thighs" only not quite so risky :wink:

i know this is off topic, but has anyone ever used vodka to clean off the thermal paste? anyone think its potentailly dangerous?

To answer the question: i usually put a dot half the size of an airsoft pellet, and when the heatsink is down, i wiggle it just a little, just to make sure its spread around.

Never used Vodka, not sure about its residue rubbing alcohol is the preferred cleaner and 70% isoprophyl is just fine.

If you work on a lot of machines you'll run across almost anything, one of my friends thought he needed to goop on the thermal compound and his machine was overheating.

I pulled his CPU and freaked out I thought he knew better I'd never seen so much thermal compound on a CPU, the entire top of the CPU was completely covered, cleaning it was going to be a nightmare trying to do it with Qtips and alcohol.

It was a job for CRC Electrical Contact Cleaner, you can find it at an Auto Parts Store, it cleans to perfection blew all the crap out of all the holes on the substrate, cleaned the CPU to the point it looked like the day he bought it and did it in about 10sec, and it will not hurt the CPU at all.

Note: CRC Electrical Contact Cleaner is flamable, use it in plenty of ventilation like outside the house, and don't smoke while using it just follow the precautions on the can and its no big deal to use. But for CPUs and GPUs that just don't seem to clean up like they should, it will clean perfectly.

I always wiggle my heatsink a little to seat it good even though some thermal compounds suggest not doing it, but I did some experimenting setting and resetting some heatsinks looking at the contact image on the heatsink, seeing just how little compound I could evenly apply and get full coverage. Always remember less is the rule, and you're filling microscopic imperfections not holes and divots.